We chronicle the use of acknowledgments in 20th‐century scholarship by analyzing and classifying more than 4,500 specimens covering a 100‐year period. Our results show that the intensity of acknowledgment varies by discipline, reflecting differences in prevailing sociocognitive structures and work practices. We demonstrate that the acknowledgment has gradually established itself as a constitutive element of academic writing, one that provides a revealing insight into the nature and extent of subauthorship collaboration. Complementary data on rates of coauthorship are also presented to highlight the growing importance of collaboration and the increasing division of labor in contemporary research and scholarship.

Web citations have been proposed as comparable to, even replacements for, bibliographic citations, notably in assessing the academic impact of work in promotion and tenure decisions. We compared bibliographic and Web citations to articles in 46 journals in library and information science. For most journals (57%), Web citations correlated significantly with both bibliographic citations listed in the Social Sciences Citation Index and the ISI's Journal Impact Factor. Many of the Web citations represented intellectual impact, coming from other papers posted on the Web (30%) or from class readings lists (12%). Web citation counts were typically higher than bibliographic citation counts for the same article. Journals with more Web citations tended to have Web sites that provided tables of contents on the Web, while less cited journals did not have such publicity. The number of Web citations to journal articles increased from 1992 to 1997.

We chronicle the use of acknowledgments in 20th century chemistry by analyzing and classifying over 2,000 specimens covering a 100-year period. Our results show that acknowledgment has gradually established itself as a constitutive element of academic writing-one that provides a revealing insight into the structural nature of subauthorship collaboration in science. Complementary data on rates of coauthorship are also presented to highlight the growing importance of teamwork and the increasing division of labor in contemporary chemistry. The results of this study are compared with the findings of a parallel study of collaboration in both the social sciences and the humanities.

The number and type of Web citations to journal articles in four areas of science are examined: biology, genetics, medicine, and multidisciplinary sciences. For a sample of 5,972 articles published in 114 journals, the median Web citation counts per journal article range from 6.2 in medicine to 10.4 in genetics. About 30% of Web citations in each area indicate intellectual impact (citations from articles or class readings, in contrast to citations from bibliographic services or the author's or journal's home page). Journals receiving more Web citations also have higher percentages of citations indicating intellectual impact. There is significant correlation between the number of citations reported in the databases from the Institute for Scientific Information (ISI, now Thomson Scientific) and the number of citations retrieved using the Google search engine (Web citations). The correlation is much weaker for journals published outside the United Kingdom or United States and for multidisciplinary journals. Web citation numbers are higher than ISI citation counts, suggesting that Web searches might be conducted for an earlier or a more fine-grained assessment of an article's impact. The Web-evident impact of non-UK/USA publications might provide a balance to the geographic or cultural biases observed in ISI's data, although the stability of Web citation counts is debatable.